date.c revision 1.39 
1/* $NetBSD: date.c,v 1.39 2005/05/15 18:39:39 dsl Exp $ */
2
3/*
4 * Copyright (c) 1985, 1987, 1988, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#ifndef lint
34__COPYRIGHT(
35"@(#) Copyright (c) 1985, 1987, 1988, 1993\n\
36	The Regents of the University of California.  All rights reserved.\n");
37#endif /* not lint */
38
39#ifndef lint
40#if 0
41static char sccsid[] = "@(#)date.c	8.2 (Berkeley) 4/28/95";
42#else
43__RCSID("$NetBSD: date.c,v 1.39 2005/05/15 18:39:39 dsl Exp $");
44#endif
45#endif /* not lint */
46
47#include <sys/param.h>
48#include <sys/time.h>
49
50#include <ctype.h>
51#include <err.h>
52#include <fcntl.h>
53#include <locale.h>
54#include <stdio.h>
55#include <stdlib.h>
56#include <string.h>
57#include <syslog.h>
58#include <time.h>
59#include <tzfile.h>
60#include <unistd.h>
61#include <util.h>
62
63#include "extern.h"
64
65static time_t tval;
66static int aflag, rflag, nflag;
67int retval;
68
69int main(int, char *[]);
70static void badformat(void);
71static void badtime(void);
72static void setthetime(const char *);
73static void usage(void);
74
75int
76main(int argc, char *argv[])
77{
78	char buf[1024], *format;
79	int ch;
80
81	setprogname(argv[0]);
82	(void)setlocale(LC_ALL, "");
83
84	while ((ch = getopt(argc, argv, "anr:u")) != -1) {
85		switch((char)ch) {
86		case 'a':		/* adjust time slowly */
87			aflag = 1;
88			nflag = 1;
89			break;
90		case 'n':		/* don't set network */
91			nflag = 1;
92			break;
93		case 'r':		/* user specified seconds */
94			rflag = 1;
95			tval = strtol(optarg, NULL, 0);
96			break;
97		case 'u':		/* do everything in UTC */
98			(void)putenv("TZ=UTC0");
99			break;
100		default:
101			usage();
102		}
103	}
104	argc -= optind;
105	argv += optind;
106
107	if (!rflag && time(&tval) == -1)
108		err(1, "time");
109
110	format = "%a %b %e %H:%M:%S %Z %Y";
111
112	/* allow the operands in any order */
113	if (*argv && **argv == '+') {
114		format = *argv + 1;
115		++argv;
116	}
117
118	if (*argv) {
119		setthetime(*argv);
120		++argv;
121	}
122
123	if (*argv && **argv == '+')
124		format = *argv + 1;
125
126	(void)strftime(buf, sizeof(buf), format, localtime(&tval));
127	(void)printf("%s\n", buf);
128	exit(retval);
129	/* NOTREACHED */
130}
131
132static void
133badformat(void)
134{
135	warnx("illegal time format");
136	usage();
137}
138
139static void
140badtime(void)
141{
142	errx(EXIT_FAILURE, "illegal time");
143	/* NOTREACHED */
144}
145
146#define ATOI2(s) ((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
147
148static void
149setthetime(const char *p)
150{
151	struct timeval tv;
152	time_t new_time;
153	struct tm *lt;
154	const char *dot, *t;
155	int len, yearset;
156
157	for (t = p, dot = NULL; *t; ++t) {
158		if (isdigit((unsigned char)*t))
159			continue;
160		if (*t == '.' && dot == NULL) {
161			dot = t;
162			continue;
163		}
164		badformat();
165	}
166
167	lt = localtime(&tval);
168
169	lt->tm_isdst = -1;			/* Divine correct DST */
170
171	if (dot != NULL) {			/* .ss */
172		len = strlen(dot);
173		if (len != 3)
174			badformat();
175		++dot;
176		lt->tm_sec = ATOI2(dot);
177	} else {
178		len = 0;
179		lt->tm_sec = 0;
180	}
181
182	yearset = 0;
183	switch (strlen(p) - len) {
184	case 12:				/* cc */
185		lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
186		yearset = 1;
187		/* FALLTHROUGH */
188	case 10:				/* yy */
189		if (yearset) {
190			lt->tm_year += ATOI2(p);
191		} else {
192			yearset = ATOI2(p);
193			if (yearset < 69)
194				lt->tm_year = yearset + 2000 - TM_YEAR_BASE;
195			else
196				lt->tm_year = yearset + 1900 - TM_YEAR_BASE;
197		}
198		/* FALLTHROUGH */
199	case 8:					/* mm */
200		lt->tm_mon = ATOI2(p);
201		--lt->tm_mon;			/* time struct is 0 - 11 */
202		/* FALLTHROUGH */
203	case 6:					/* dd */
204		lt->tm_mday = ATOI2(p);
205		/* FALLTHROUGH */
206	case 4:					/* hh */
207		lt->tm_hour = ATOI2(p);
208		/* FALLTHROUGH */
209	case 2:					/* mm */
210		lt->tm_min = ATOI2(p);
211		break;
212	case 0:					/* was just .sss */
213		if (len != 0)
214			break;
215		/* FALLTHROUGH */
216	default:
217		badformat();
218	}
219
220	/* convert broken-down time to UTC clock time */
221	if ((new_time = mktime(lt)) == -1)
222		badtime();
223
224	/* set the time */
225	if (nflag || netsettime(new_time)) {
226		logwtmp("|", "date", "");
227		if (aflag) {
228			tv.tv_sec = new_time - tval;
229			tv.tv_usec = 0;
230			if (adjtime(&tv, NULL)) {
231				perror("date: adjtime");
232				exit(1);
233			}
234		} else {
235			tval = new_time;
236			tv.tv_sec = tval;
237			tv.tv_usec = 0;
238			if (settimeofday(&tv, NULL)) {
239				perror("date: settimeofday");
240				exit(1);
241			}
242		}
243		logwtmp("{", "date", "");
244	}
245
246	if ((p = getlogin()) == NULL)
247		p = "???";
248	syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
249}
250
251static void
252usage(void)
253{
254	(void)fprintf(stderr,
255	    "usage: %s [-u] [-r seconds] [+format]\n", getprogname());
256	(void)fprintf(stderr, "       %s [-anu] [[[[[cc]yy]mm]dd]hh]mm[.ss]\n", getprogname());
257	exit(1);
258	/* NOTREACHED */
259}
260